The U.S. Geological Survey released their updated National Seismic Hazard Maps, showing 42 of the lower 48 states have a reasonable chance of facing damage from ground shaking in the next 50 years. Last updated 6 years ago, these new maps were developed with new ground motion models and compare changes between the 2008 maps and the 2014 ones.
The highest risk is on the west coast, intermountain west, and several clusters in the central and eastern United States. That really hasn’t changed since the 2008 map; instead, the potential severity and strength of earthquakes was upgraded for those areas based on new data. For example, risk was upgraded in the eastern United States and the New Madrid Zone based in part on recent earthquakes there.
The Pacific Northwest’s risk was upgraded due to similarities between its seismic hazards and those of Japan and Chile, both of which experienced very strong earthquakes in the past several years. New faults recently discovered in parts of California lead to increased hazard estimates there.
The report is essential for anyone involved in risk analysis, earthquake resistant construction and engineering, building codes, or emergency preparedness planning.